DETROIT (WJBK) - We are learning more about a hit-and-run accident that killed an 8-year-old boy.

On Wednesday we heard testimony from a man who witnessed the tragic crash. Witness Nathan Dennings described what happened when 8-year-old Brandyn Starks was killed.

He testified that, after the driver hit the boy, the vehicle merged over one lane to the right and drove faster.

The Wayne County Prosecutor's Office charged Stephen Williams with reckless driving causing death, operating with a suspended license and failure to stop at the scene of an accident. Investigators say he was behind the wheel of a Chevy Tahoe that struck Starks in southwest Detroit back in April. The boy was walking to a park on Fort Street near Miami when he was killed.

Detroit Police Sgt. Paul Warner also testified. He's an accident reconstructionist, and detailed how fast Williams was driving before allegedly hitting the boy.

He testified that their report goes back to five seconds before the crash, and in those five seconds his speed varied between 68 - 69 mph.

Warner also testified that Williams hit the brakes one second before striking Starks. Witnesses say he should have taken a cue from other drivers.

The prosecutor asked Dennings if he saw what other drivers were doing, when they noticed the boy with his wagon.

"Yeah they came to a complete stop," Dennings testified. "Also I did."

Prosecutor: "The vehicle to the right of you and you came to a complete stop why was that?"

"It seemed like the boy was about to run," he said.

Detroit Police tracked Williams down just a few days after the accident, thanks to an anonymous tipster who called FOX 2 and told us it was Williams behind the wheel.

The 27-year-old was on probation for a drug conviction. Williams' preliminary exam was put on hold Wednesday as the court tries to track down another witness.